1. Field of the Invention
The present invention relates to rescue tools and particularly to a divers knife.
2. Description of the Prior Art
First responders to maritime accidents and rescue are typically involved in scuba or free dives to a vehicle or the like which may be submerged in murky water, oftentimes with an occupant having a limited supply of oxygen and sometimes suffering from injury. Popular amongst many such divers are robust diver's rescue knives that typically include a longitudinal blade which may be formed on one side with a sharp edge, on the other side with a corrugated edge and sometimes on the distal extremity with a chisel or pry element. Such knives typically include a relatively robust axial handle and in many instances include a butt end having an axially projecting threaded stud which receives a threaded cap to close off the butt end. Such devices, however, suffer the shortcoming that neither the conventional blade or handle are effective for breaking the glass in a submerged vehicle.
Automobiles and other passenger vehicles are typically manufactured with shatterproof windshields and relatively hard side windows which are challenging to break, particularly underwater where the divers arm movements are resisted by the surrounding water thus dampening efforts to apply a sharp impact to the window area for gaining access.
In many instances, the doors of the vehicles may be damaged and, in any event, for submerged vehicles the water pressure against the exterior of the doors, particularly when multiplied over the total area of the doors, affords a high force resisting swinging of the free edge of the latch edge of the doors outwardly, thereby restricting access. Thus, it is desirable that the diver be equipped with a rescue tool effective to break the glass windows for access to the interior of the vehicle.
In recognition of this need, many different devices have been proposed as a tool for breaking the glass of various windows in the event of an emergency. Typical of these devices are spring loaded keychain devices which may incorporate a spring loaded impact device for striking the surface of a window, various types of hammers and access tools with round or pointed ends for striking the window. Many first responding divers prefer to carry with them a limited number of tools, typically mounted from the belt, arm or other convenient location for ready access in the case of the emergency dive. Most such divers carry with them a rescue knife which is necessary for cutting through various restraints and prying loose different components at an emergency scene.
Multipurpose tools are known in the art. It has been recognized that it would be beneficial to incorporate a punch tool in a rescue knife to thus provide one tool effective to serve the purposes of a knife and a window punch. In this regard various different styles of window punches have been proposed including custom knives which incorporate a punch on the handle end which may be pivoted between retracted and extended positions. Such devices are relatively expensive to manufacture and thus out of reach for many first responders operating on a limited budget. Also, many of these punches suffer the shortcoming that the punches do not include a sufficiently sharp point or sufficiently hard point located on the axis of the knife so that a diver can readily apply a high magnitude of force by quickly grasping the handle and applying a striking blow to a window surface.
It has been proposed to incorporate a window punch in a seat belt cutter to provide a laterally projecting punch. A device of this type is shown in U.S. Pat. No. 5,630,242 to Oginaezawa. Such devices suffer the shortcoming that they have little applicability underwater because sufficient force cannot be applied in the lateral direction to effectively break a typical shatterproof window.
Other devices with the laterally projecting punches include U.S. Pat. No. 5,903,942 to Hasegawa which shows a combination cutter and hammer device.
It has also been proposed to construct a knife which receives a conical cap over the knife and formed with a punch which may be utilized in punching a window. A device of this type is shown in U.S. Pat. No. 6,467,114 to Sigl. Such devices are relatively expensive to manufacture and are typically priced out of the budget of a public employee who would regularly be involved in Harbor Patrol and Coast Guard rescue service.
Other proposals have been made to construct a jackknife with a punch incorporated on one end of the handle. A device of this type is shown in Chinese Patent Publication No. 201415411 published 3 Mar. 2010. Such a foldable jackknives are not generally accepted as readily accessible tools for divers.
Knives have been proposed incorporating various punch devices on the butt end of a knife. In US Application No. 2006/0080840 by Freeman, a knife is disclosed which includes a punch for connection to the butt end of a knife through a relatively complicated connection means. US Publication No. 2008/022895 to Marifone et al. shows a punch at the butt end of a knife which includes a spherical ball for contact with the window.
Thus, until the present invention, rescue divers were faced with a dilemma either invest in a window punch as a separate tool to add to the inventory of devices which must be available on their person underwater, or invest in a new rescue knife with a punch which may be ineffective in many instances to achieve the desired results of effectively shattering the window of a submerged vehicle.